Fracture of polycrystalline Fe−2.3%V−0.12%P alloy

Fracture experiments on a polycrystalline Fe-2.3mass%V-0.12mass%P alloy show that the fracture mode is directly related to the grain boundary segregation of phosphorus. Comparison of the experimental data with theoretical simulations showed that intergranular fracture spreads along those grain boundaries, which contain more than 17 at.% of segregated phosphorus.     

俄歇化学位移影响因素分析

对几种硅化物及金属氧化物的俄歇化学位移作了实验研究。基于现有的化学位移的两个理论模型（电荷势模型和弛豫能模型），提出了俄歇化学位移的半经验计算关系式。概括了俄歇化学位移与元素的化合价、相邻原子的电负性差以及极化能（离子有效半径）之间的关系，实验结果与理论计算相一致。     

Influence of vanadium on grain boundary segregation of phosphorus in iron and iron-carbon alloys

The influence of vanadium on grain boundary segregation of phosphorus has been studied in iron and iron-carbon alloys by means of fracture experiments in a scanning Auger microprobe. The emphasis here is to study the effects of vanadium on the interaction processes operative under circumstances when structure in the interior of the grain (in the present case carbide formation) and grain boundary segregation form simultaneously. It is emphasized that to predict and analyse the behaviour of an alloy, it is important to consider atomic interactions both at the grain boundaries and in the grain interior and that between the constituents and the grain boundaries. The study suggests that the principal determining factor in the scavenging or retardation of migration of phosphorus to the grain boundaries is whether vanadium is present in the combined form (say, carbide) or is available in solid solution form. When vanadium is present in solid solution form, grain boundary segregation of phosphorus is low because of the chemical interaction of vanadium and phosphorus. However, as carbon is increasingly introduced in the alloy, vanadium now preferentially reacts with carbon in view of higher interaction for carbon as compared to phosphorus. A consequence of this is the increase in the grain boundary concentration of phosphorus. In such a situation the presence of excess carbon in addition to what is stoichiometrically required to precipitate the entire vanadium as vanadium carbides, serves as a palliative with regard to the reduction in the intergranular concentration of phosphorus. This palliative behaviour is explained in terms of the sitecompetition model. An effort is also made to examine the behaviour of segregating elements in terms of whole range of probable interactions (both at the grain boundaries and in the grain interior) and chemical interaction energies.     

俄歇电子能谱的峰形修正与峰形分析

介绍一系列峰形修正的方法——包括本底的扣除、仪器响应函数的修正、非弹性散射影响的消除等,并将其应用于Si(100)表面的俄歇峰形分析中,对于L_(23)VV,L_1L_(23)V峰取得了与理论计算符合很好的结果,从中可以提取出丰富的价带局域电子态信息。     

氮化钛薄膜的高分辨AES谱和XPS谱研究

着重讨论了TiNx薄膜俄歇电子谱的定量分析方法和X射线光电子谱中线形的变化。利用已知组元强度定量分析技术和Ti的LMV俄歇电子峰，探讨TiNx薄膜中N含量的定量方法。由该方法给出的定量结果与X射线光电子谱定量结果相一致。同时，利用X射线光电子谱测定了TiN和Ti2N2p轨道的结合能。并针对Ti2p峰形随N含量的变化，给出新的解释。     

合金氧化膜的AES分析技术及其应用研究

根据俄歇电子能谱（AES）的深度分布图，得到不同区域的膜厚和在此区域中的元素富集因子与材料性能之间的关系。并以304不锈钢在高温水中生成的氧化膜为例，探讨膜厚和元素铬的富集因子与材料抗应力腐蚀性能之间的关系。     

电子束、离子束与蓝宝石相互作用的研究

研究了电子束、离子束作用于Al2O3表面时成分的变化，表明无论电子束或离子束都能使Al2O3发生分解，产生导电的元素Al。实验在PHI610·SAM上进行，电子束轰击下（3keV，O．5μA，入射角60°）10s就有元素Al分解出来，2min以后就达到饱和，分解析出量随时间成a（1－e－bt）的关系。离子束轰击下同样发生元素Al的分解，但当Ei＞3keV时，由于剥离速率加大，溅射5min时表面Al峰反而比1min时要弱。这时表面Al含量处于分解析出与溅射剥离的动态平衡中。实验还发现了Al2O3的解析与表面成分有关（如碳的含量）。最后讨论电子束与离子束的解析机理。     

Effect of heating on the behaviors of hydrogen in C-TiC films with auger electron spectroscopy and secondary ion mass spectroscopy analyses

C-TiC films with a content of 75% TiC were prepared with magnetron sputtering deposition followed by Ar⁺ ion bombardment. Effect of heating on the behaviors of hydrogen in C-TiC films before and after heating was studied with Auger Electron Spectroscopy and Secondary Ion Mass Spectroscopy (SIMS) analyses. SIMS depth profiles of hydrogen after H⁺ ion implantation and thermal treatment show different hydrogen concentrations in C-TiC coatings and stainless steel. SIMS measurements show the existence of TiH, TiH₂, CH₃, CH₄, C₂H₂ bonds in the films after H⁺ ion irradiation and the changes in the Ti LMM, Ti LMV and C KLL Auger line shape reveal that they have a good hydrogen retention ability after heating up to the temperature 393 K. All the results show that C-TiC coatings can be used as a hydrogen retainer or hydrogen permeable barrier on stainless steel to protect it from hydrogen brittleness.     

Carbon and sulphur on Pd(111) and Pt(111): Experimental problems during cleaning of the substrates and impact of sulphur on the redox properties of CeOx in the CeOx/Pd(111) system

The X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and CO titration has been used to detect common impurities like carbon and sulphur on Pd(111) and Pt(111) surfaces. Different experimental problems are discussed and practical tips for the cleaning of Pd(111) and Pt(111) are given. A mechanism for the carbon oxidation on closed packed platinum group metals like Pt(111) and Pd(111) is presented. The bulk carbon concentration of Pd(111) was estimated based on the Langmuir-McLean theorem. Additionally it was shown that the titration with CO and subsequent XPS measurement is a powerful yet convenient method for quantitative detection of impurities and ceria coverage determination. A CeO_x/Pd(111) inverse model system was prepared by evaporation of cerium in an oxygen atmosphere. The comparative study has shown that sulphur contamination changes the redox properties of the CeO_x in the CeO_x/Pd(111) system.     

高温度梯度改进单晶高温合金的性能

对比了高温度和低温度梯度下ＮＡＳＡＩＲ１００单晶的组织和高温持久性能，发现高温度梯度降低单晶中显微疏松含量，减小树枝晶间距和显微偏析程度，使单晶具有较少的γ／γ共晶和较细的，形状较规则的γ沉淀，在相同的抽拉速率下，高温度梯度提高铸态ＮＡＳＡＩＲ１００单晶的高瘟持久寿命可达１１倍多。固溶处理进一步改进单晶的组织和高温持久性能。